A client’s retirement date may be the most important variable in a financial plan.

It is crucial that advisers know how to help clients pick the right date and plan for it, though the exact date can be fine-tuned later on.

“You might consider making a pre-retirement checklist of key questions to ask every client who is talking about stopping work so they can see the whole picture and consider all aspects of the process early on,” says Lauren Locker, a CFP and the principal of Locker Financial Services in Little Falls, N.J.

As retirement approaches, the answers to those questions can sometimes help determine the precise date.

“For example, do you want a retirement date to coincide with a tax year, ending Dec. 31, or a fiscal year, ending June 30?” Locker asks.

If a client’s company has a pension plan, it is important to know whether working just a bit longer would put the client in a better position with earned credit, she says.

For those lucky enough to have a pension, external factors such as interest rates may play a role in timing as well, says Suzanne Shier, wealth planning practice executive and chief tax strategist/tax counsel at Northern Trust in Chicago.

“It’s generally more advantageous for people who are looking to take a lump sum to do that before there’s an increase in interest rates,” she says. “So we see people who ask, ‘Should I retire this year or next year?’ because they’re monitoring interest rates.”

Clients’ Social Security-claiming strategies will have an impact on when they retire, as will Medicare eligibility.

Locker also says that some companies require 20 years of employment in order to qualify for retiree health benefits, so timing might be crucial in that case, as well.

Target retirement dates are an important topic of discussion even for clients whose retirement isn’t imminent.

“It’s always a relevant question, but its implications are different, depending on where someone is in their career,” Shier says.

For example, during higher earning years, clients need to understand how to make forward-looking decisions about retirement without being overly optimistic that their income will continue to increase or even stay the same, she says.

Advisers should make sure that clients really grasp that each additional year worked is another year to build up reserves and one less year of dependence on retirement savings.

“It’s common knowledge, but I don’t think that it can be assumed that everyone really appreciates it, and having the planner walk through that with the client can be extraordinarily powerful,” Shier says.

Clients early in their careers won’t be able to pinpoint retirement dates, but that isn’t a problem, she says.

“If you’re talking about a client who is younger, embrace the uncertainty,” and use it to demonstrate the importance of early planning and taking advantaged of compounded interest and employer matching contributions, Shier says.

“Certainty about a retirement date is not a pre-requisite to planning,” she says.

This story is part of a 30-30 series on preparing for retirement.